Those who take the risk of driving under the influence can cause untold harm and misery to themselves and others. They could get caught and end up behind bars, spend a hefty amount on lawyers, get their drivers’ license suspended, spend an unreasonably high amount on insurance, and have a permanent record affecting their career and life. The other option would be to buy a personal breathalyzer and use it to find out if taking a cab back home would be the wiser option.

Devices are available in the market from just $3 up to $300. As you might expect, cheaper models can compromise on quality, and opting for a cheaper device can therefore be more dangerous. Carrying a breathalyzer is imperative nowadays considering the strictness of law regarding DUI, and countries like France have made it mandatory for drivers to carry one with them at all times.

The portable device for measuring the Blood Alcohol Concentration (BAC) was perfected by Robert F. Borkenstein, a forensic scientist with the Indiana State Police in 1954. There are many different types of personal breathalyzers available these days.

Fuel Cell: This type gives almost the same readings as the ones used by law enforcement officials. On interacting with the alcohol in the breath, the fuel cell sets off an electrical charge and outputs a precise BAC reading. There are also vending machines available in some bars and restaurants like the “Boozelator 3001” breathalyzer which uses fuel cell technology. Price range: $100 - $300

Semiconductors: Breathalyzers using semiconductors to measure the alcohol levels come in varied qualities. The trustworthiness of the product is dependent on the type of material used, with silicon-based semiconductors showing greater accuracy and commanding higher prices. Semiconductors tend to degrade over time and require expensive and inconvenient periodic calibration. Price range: $85 - $25.

Crystals: These can only be used for a single time. Popular in the military, they are fairly accurate. The crystals turn color when the BAC levels cross a certain mark. Price range: $3

Smartphone Apps and Key chains: These normally cost less than $50 and, although convenient, their reliability is questionable.

Which one should you choose?

There are certain standards to keep in mind while selecting a personal breathalyzer. A breathalyzer is good as long as it is accurate. Highest ratings run to +-0.0005 with experts recommending devices with accuracy levels up to +-0.01. Also, note that you should use the device at least 20 minutes after your last cigarette or drink. Practice using the device at home before taking it out.

FDA 510(k) Certification: Breathalyzers are considered to be medical devices by the Food and Drug Administration. They approve its usage after testing. Devices with no certifications can be inaccurate. Accurate breathalyzers have a removable and washable mouthpiece attached to the device to prevent contamination of reading from smoke and air pollutants. The certification must also be cleared from the U.S. Department of Transportation (DOT) for professional screening. Clearances from both these authorities ensure that the product has been tested and reviewed “safe and effective” for use. DoT basically clears two types – EBT’s (Evidential Breath Testers) that include fuel cell devices and ASD’s (Alcohol Screening Devices) which have semi-conductors.

Calibration: Quality dependable breathalyzers require calibration by manufacturers at some point, although there are models available in the markets that carry a replaceable sensor module. Prices for calibration ranges from $20 to $50. It is recommended to recalibrate every 300 tests or once a year for semi-conductors while fuel cell ones will remain accurate for thousands of tests, but it is always safer to do the recalibration annually. Using a breathalyzer often makes sure it stays accurate.

Pre Calibration: Some breathalyzer distributors, such as AlcoHawk (www.breathalyzers.com) require that breathalyzers are calibrated at the point before they are shipped to customers, rather than at the point of manufacture. This is because breathalyzers often lose their calibration quickly under intense shipping conditions, especially across large distances if they are shipped from overseas.

Instructions: With some devices, you blow into them, while others require that you blow and suck and blow again. There are also models that need you to hum a tune into them. Understand and follow instructions to get accurate readings. Check the brands and go for dependable ones that must have the aforementioned certifications.